Loudspeaker with distributed driving of the membrane

Abstract

The membrane of a loudspeaker, which is driven on a limited part of the membrane, does not move completely like the tone current. For example, a cone, which is driven in the top, provides more accurate driving by also being driven in the periphery from the drive system back where the movement of the sound coil also is taken out. The driving can e.g. be distributed with a cone of net. With separate sound coils from the front side and back side of the driving system, the loudspeaker properties can be optimised. The biggest benefit is achieved with a long loudspeaker where the movement is taken out from the back side of the long drive system and distributed with plates, cones and wavy walls to a bulgy membrane edges.

Description

PRIOR APPLICATION [0001]This is a continuation-in-part patent application that claims priority from US patent application Ser. No. 11 / 569,672 filed 27 Nov. 2006 that claims priority from International Application No. PCT / SE2005 / 000772, filed 25 May 2005, claiming priority from Swedish Patent Application No. 0401365-2, filed 28 May 2004.BACKGROUND AND SUMMARY OF THE INVENTION [0002]There is too much sound produced today causes damage to the ear. In the ear there are muscles which can be tired. Therefore, after a period of exposure, injures may arise from reasonable high sound levels.[0003]One object of the present invention is to produce a sound system which with high quality only gives off the sound level needed at all places in the whole space intended.[0004]A long and narrow loudspeaker along a whole wall has the following advantages:[0005]The listeners closest to the sound system are all exposed to the same sound levels.[0006]No or only insignificant reflections arise from the si...

AI Technical Summary

Benefits of technology

[0004]A long and narrow loudspeaker along a whole wall has the following advantages:

[0007]The sound pressure drops relatively slowly so that listeners at distance from the loudspeaker maintain a good sound level without the nearest listeners having to be exposed to painfully high levels.

[0009]The air retains its linear properties, so distortion caused by high sound pressure does not occur. The sound coil movement gets small amplitude, so that the distortion in the driving system will be low.

[0010]If one wants to further improve the propagation of the sound, it can be relatively easily reflected and bent because the material for this will have cylindrical surfaces. Driving systems with reduced force may be used e. g. reduced magnetic field in electro-dynamic driving system. Even geomagnetic fields may be used if they are at first concentrated.

Problems solved by technology

There is too much sound produced today causes damage to the ear.

Therefore, after a period of exposure, injures may arise from reasonable high sound levels.

The basic problem of conventional loudspeakers is that the cone in order to produce bas tones shall be large, at which the treble tones at the best make a propagating wave outwards in the cone.

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